Parents and concerned community members, including supermodel Cindy Crawford and "Scandal" actor Josh Malina, spoke at a rally in Malibu Tuesday to protest the toxic levels of cancer-causing chemicals found at Malibu schools and urge additional testing of school facilities.

At the rally, Crawford, a Malibu resident and mother of students at the local high school, said she and her husband are willing to pay for testing for contaminants at the schools.

"Without confirming where the PCBs are, we cannot ensure our children are not being exposed," Crawford said.

The rally is the latest action in a nearly year-long battle between the Santa Monica-Malibu Unified School District and parents over the high levels of PCBs found in soil and caulk samples around Malibu middle and high schools and nearby Juan Cabrillo Elementary School.

Malibu HS Parents Meet With Environmental Expert

Nearly a dozen classrooms at Malibu High School were shuttered after three teachers were diagnosed with thyroid cancer. Mold and rat droppings were found in the rooms, but they were deemed safe. Now, parents are waiting on further results to determine if there are carcinogens at their children's school. Ten Chen reports from Malibu for the NBC4 News at 5 p.m. on Oct. 24, 2013. (Published Thursday, Oct 24, 2013)

According to the Environmental Protection Agency, PCBs cause cancer and used to be commonly used as building materials.

Local interest groups such as Malibu Unites and Public Employees for Environmental Responsibility (PEER) have tied these high levels to instances of thyroid cancer and other illnesses in teachers.

The two groups submitted independent test results to the EPA that indicate the levels of PCBs in Malibu High School and Juan Cabrillo Elementary School are thousands of times higher than the legal limit of 50 parts-per-million.

A report from BC laboratories in July found levels of PCBs thousands of times higher than legal limits in some locations across the district.

"I have lost some of my confidence in our school board and their promise to keep our students and our teachers safe," Crawford said at the rally.

Malina echoed Crawford’s sentiments and called on the EPA to enforce the Toxic Substances Control Act of 1976, a federal law that regulates testing and restrictions on certain chemicals, including PCBs.

In a letter sent to the Malibu community in July responding to the test results District Superintendent Sandra Lyon chided the groups for collecting samples secretly "in a manner that was most certainly designed to incite concerns."

Malibu Unites President Jennifer deNicola said the tests were done at the same independent labs previously used by the EPA.

DeNicola added she expects many parents to keep their children home when school starts next week.